Jam-ojisan crafted Anpanman when a shooting star landed in his oven, miraculously bringing the anpan pastry to life. This event established him as the foundational guardian and provider.

Extensive travels during his youth granted him vast knowledge across diverse fields like culinary arts, mechanics, and general wisdom. This expertise allows him to invent functional machinery such as the Anpanman Mobile and repair mechanical characters. His culinary proficiency extends beyond baking, reinforcing his identity as a nurturing sustainer.

His character embodies unwavering compassion and sacrifice. He continuously bakes replacement heads for Anpanman whenever the hero's head is compromised by water, dirt, or acts of selflessness—such as feeding pieces to the hungry. This cycle of creation and replenishment reflects themes of resilience and generosity.

His relationships define his character dynamics. He shares a familial bond with Anpanman, whom he raised and mentors to uphold justice. With his bakery assistant, Batako-san, he maintains a close, non-familial kinship marked by mutual care; their history suggests an association dating back to her infancy. He extends paternal support: acting as a father figure to Melonpanna, encouraging Creampanda’s growth as an adoptive guardian, and repeatedly inviting the isolated Rollpanna to join the bakery despite her dangerous dual-hearted condition. His role in creating certain heroes like Currypanman remains ambiguously referenced across media.

His existence as a "fairy" clarifies the absence of ordinary humans. Early manga depictions featured him smoking a pipe, omitted in later adaptations.